Antifoulants are commonly used to inhibit the attachment and growth of marine organisms on the hulls of ships. The buildup of such organisms leads to significant drag and results in increased fuel costs and longer ship dry-dock times. Organotin compounds have been used successfully as antifoulants but with the unfortunate consequences that they have relatively long half-lives, have a tendency to bioaccumulate, and are chronically toxic to marine life.
This module describes an environmentally preferable antifoulant, SEA-NINE (trademark) 211. Evidence for its effectiveness is presented. The environmental risk for the active ingredient in SEA-NINE 211 is examined and its risk quotient is described. Unlike organotin compounds, SEA-NINE 211 undergoes rapid degradation in the marine environment, thereby decreasing bioaccumulation and chronic toxicity. The module is appropriate for an environmental chemistry course during discussions of pesticides and/or water pollution and includes the structures of tributyltin oxide (an organotin compound) and the active ingredient in SEA-NINE 211, 18 questions, "Notes to Instructors," and a PowerPoint presentation.
Summary prepared July 2005 by Marin Robinson, Department of Chemistry and Biochemistry at Northern Arizona University.
Cann, M. C. Antifoulants (Marine Pesticides). http://academic.scranton.edu/ faculty/ CANNM1/ environmental.html (accessed June 2011).